Optimization of trace elements in purified glycerol for microbial lipid and citric acid production by Yarrowia lipolytica SKY7

Abstract

Purified glycerol obtained after acid treatment of crude glycerol solution was used as the carbon source for lipid and citric acid production using Y. lipolytica SKY7. Although purified glycerol was high in phosphorus, it was important to investigate the impact of fortification of trace elements in the medium on cell growth, lipid and citric acid (CA) production. When all the trace elements (including phosphates and sulfates) required for growth and lipid production were added to the purified glycerol medium, high biomass (51.67 g/L) and lipid concentration (19.47 g/L) were observed at 96 h of fed-batch fermentation with low CA concentration of 5.42 g/L. The purified glycerol medium without additional trace elements gave low biomass (27.67 g/L), lipid concentration (9.35 g/L) at 80 h of fed-batch fermentation, but gave high CA concentration (24.51 g/L). When purified glycerol was provided with only sulfates or all elements except KH 2 PO 4 , low biomass (32.59 g/L and 38.52 g/L) and citric acid concentration (1 g/L and 2.42 g/L) were obtained at 96 h.

Current advances for omics-guided process optimization of microbial manufacturing

“…The results showed that the trace elements in purified glycerol were not enough for cell growth and lipid production, resulting in low biomass (27.67 g/L) and lipid titer (9.35 g/L). Thus, by external adding trace elements (in the form of phosphates and sulfates), a higher biomass (51.67 g/L) and lipid titer (19.47 g/L) were finally obtained (Kumar et al 2021 ).…”

A Review on Citric Acid Production by Yarrowia lipolytica Yeast: Past and Present Challenges and Developments

“…In addition, CA production is stimulated by Mn 2+ [84]. Researchers often use tap water rather than a microelement solution [48,53,56,85].…”